High gradient magnetic separator

Abstract

In a high-gradient magnetic separator for the selective separation of magnetic particles from a suspension which is conducted through a matrix of plate-like separation structures of a magnetic material which are disposed in a magnetic field and through which the suspension is conducted, alternate plates of the separation structures are movable relative to the other plates which are stationary and are all mounted on a carrier by which they can be moved relative to the stationary plates at least during cleaning of the plates for the removal of magnetic particles collected on the plates.

Description

BACKGROUND OF THE INVENTION[0001]The invention relates to a high-gradient magnetic separator for the selective separation of magnetic particles from a suspension.[0002]The separation of ferro-, ferri- or para-magnetic particles from liquid or gaseous fluids by magnetic separators is a basic concept of chemical engineering used in numerous variants. A particular advantage of the principle of the magnetic separation resides in the possibility to selectively separate magnetic particles from a mixture with other, non-magnetic particles. The selection of the magnetic separator is based on the size and the magnetic properties of the particles.[0003]Relatively large and highly magnetic particles such as magnetite ores with particle sizes >75 μm can be separated with simple drum or band separators. Finer, strongly magnetic particles up to a size of 10-20 μm can still be separated from an aqueous suspension by special drum separators. Yet finer particles in the micrometer range (about 0.1...

AI Technical Summary

Benefits of technology

[0016]For the cleaning of the matrix which is necessary in certain intervals, the provision of the relatively movable groups of separation areas mentioned above represent a significant improvement.

[0017]The matrix is cleaned preferably in a counter-current principle using a flushing fluid wherein the relative movement of at least two of the separation area structures generates in the flushing fluid turbulence, which, in combination with inertia—, that is centrifugal and gravity forces significantly enhances the release of the magnetic particles from the separation surfaces. Even with some magnetism remaining, this permits cleaning even under the influence of a magnetic field. In certain cases only the provision of such additional forces makes the release possible.

Problems solved by technology

In addition, the desire to keep the volume of the flushing fluid as small as possible, and to hold the required pumping power down the amount of the flushing fluid used and the flow speed of the fluid that can be obtained during flushing are limited.

As a result, removal of the particles is only incomplete.

Particularly particles with a high remnant magnetism are hard to remove.

Consequently, these particles continue to strongly adhere to the matrix wires, which detrimentally affects the clean-up efficiency to a significant degree.

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